A suspected case of Severe Acute Respirator Syndrome has been detected in Co Mayo.
It is believed a middle-aged man who had recently returned from the Far East was taken to Mayo General Hospital, Castlebar, with symptoms of the disease.
The Western Health Board is treating it as a "probable" case of the killer strain of pneumonia, which has killed several people around the world.
Last night it was confirmed that two patients being treated in Dublin were not suffering from SARS.
In a joint statement, the Department of Health and the National Disease Surveillance Centre - the expert group set up by the Minister for Health, Mr Martin - said they would continue to meet, monitor and advise as necessary.
Joint statement by the Department of Health and Children, National Disease Surveillance Centre and Western Health Board
In response to advice from the World Health Organisation, Ireland, in common with most countries, has been investigating illness in people who have travelled in areas affected by Severe Acute Respiratory Syndrome (SARS).
The Western Health Board's Department of Public Health is investigating a probable case of SARS in a person who has recently returned on a flight from South East Asia and who has shown symptoms similar to those of the disease.
The WHB will continue to closely monitor the situation in co-operation with health professionals and the NDSC.
The expert group established by Mr Micheál Martin TD, Minister for Health and Children continues to monitor the situation and will advise him of any further measures which may need to be taken as the situation develops.
The NDSC and the Department have developed and disseminated guidance to hospitals and professionals in the health services describing this syndrome and offering advice as to how suspected cases should be dealt with.
The symptoms of SARS are a temperature of over 38°C, flu-like symptoms and a cough. This is relevant only to people who have been in the affected areas. The advice to the general public remains as before: people travelling to affected areas in Hong Kong, Vietnam, Singapore and Guandong Province in China should be aware of the symptoms and seek medical advice should they become unwell during their trip or within 10 days of leaving the area.
The NDSC, in collaboration with Departments of Public Health throughout the country, continues to conduct surveillance of SARS in Ireland.